[Bug] PX4 Mission as relative altitude results in inconsistent execution of missions

[Jaeyoung-Lim]

Describe the bug

Currently a waypoint in PX4 consists of the following fields

• latitude (WGS84)
• longitude (WGS84)
• relative_altitude

The problem is that given the same mission file, a mission execution would be different depending on where the vehicle starts. Even worse, when the vehicle is started from the same position, the vehicle will fly different altitudes depending on where the EKF origin is initialized.

This can become even worse when the local origin resets, changing the mission locations depending on where the origin is.

Mavlink also seems to not specify what the altitude field means for the MAV_CMD_DO_REPOSITION

To Reproduce

1. Fly a mission
2. Restart the vehicle in a different altitude
3. Fly another mission

Expected behavior

With a same mission file, the vehicle flies the same sequence of positions.

Screenshot / Media

No response

Flight Log

No flight log

Software Version

Latest main

Flight controller

All

Vehicle type

None

How are the different components wired up (including port information)

No response

Additional context

• In order to interpret a mission, a local origin needs to be queried: Remove global origin received ethz-asl/terrain-navigation#59

[Jaeyoung-Lim]

You can define the origin of a mission in absolute altitude. Closing